test(memory): 添加线程记忆更新器 JSON 修复测试

验证 update_memory 在模型返回包含未转义内部引号的 JSON
时能正确解析并保存用户偏好和事实数据。

backend/tests/test_thread_memory_updater.py

@@ -1,3 +1,5 @@
+from unittest.mock import patch
+
 from deerflow.agents.memory.thread_updater import ThreadMemoryUpdater
 
 
@@ -18,3 +20,65 @@ def test_scrub_sensitive_tolerates_non_numeric_confidence():
     assert len(cleaned["facts"]) == 2
     assert cleaned["facts"][0]["confidence"] == 0.5
     assert cleaned["facts"][1]["confidence"] == 0.5
+
+
+def test_update_memory_repairs_model_json_with_unescaped_inner_quotes():
+    class _Storage:
+        def __init__(self):
+            self.saved = None
+
+        def load(self, _thread_id):
+            return None
+
+        def save(self, _thread_id, data, expected_version=None):
+            self.saved = {
+                "thread_id": _thread_id,
+                "data": data,
+                "expected_version": expected_version,
+            }
+            return True
+
+    fake_storage = _Storage()
+    fake_model = type(
+        "M",
+        (),
+        {
+            "invoke": lambda self, prompt: type(
+                "R",
+                (),
+                {
+                    "content": """
+{
+  "user": {
+    "topOfMind": {
+      "summary": "反感“作为 AI"这种句式，认为回答不用寒暄直接说重点。",
+      "updatedAt": "2026-06-11T07:13:11Z"
+    }
+  },
+  "history": {},
+  "facts": [
+    {
+      "content": "偏好直接回答，不喜欢“作为 AI"式开场",
+      "category": "preference",
+      "confidence": 0.92
+    }
+  ]
+}
+""".strip()
+                },
+            )()
+        },
+    )()
+    messages = [type("Msg", (), {"type": "human", "content": "请直接回答重点，不要寒暄。"})()]
+
+    with (
+        patch("deerflow.agents.memory.thread_updater.get_thread_memory_storage", return_value=fake_storage),
+        patch.object(ThreadMemoryUpdater, "_get_model", return_value=fake_model),
+    ):
+        result = ThreadMemoryUpdater().update_memory(messages, "thread-test")
+
+    assert result is True
+    assert fake_storage.saved is not None
+    assert fake_storage.saved["expected_version"] == 0
+    assert fake_storage.saved["data"]["user"]["topOfMind"]["summary"].startswith("反感“作为 AI")
+    assert fake_storage.saved["data"]["facts"][0]["content"].startswith("偏好直接回答")